Joint member

Abstract

This joint member comprises a first evaporator (15) and a second evaporator (16) connected in parallel to each other, and is used in a refrigeration cycle (10) configured to be able to block inflow of a refrigerant containing refrigerator oil into the second evaporator. A joint member (100) comprises a first refrigerant flow path (101), a second refrigerant flow path (102), a merging portion (13b), and a compressor-side flow path (103). The refrigerant flowing out from the second evaporator flows in the second refrigerant flow path. The second refrigerant flow path comprises an upstream portion (102a), a downstream portion (102c), and a connection portion (102b), and the downstream portion is disposed on the lower side in the gravity direction with respect to the upstream portion.

Description

Joint material CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2024-098908 filed on June 19, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a joint member used in a refrigeration cycle in which a plurality of evaporators are connected in parallel.

[0003] In a conventional refrigeration cycle in which multiple evaporators are connected in parallel, a technique related to a joint member including a confluence portion where refrigerant flowing from each evaporator converges is disclosed in Patent Document 1. Patent Document 1 discloses a technique related to a confluence portion of a refrigeration cycle configured to prevent refrigerant from stagnation in any one of the multiple evaporators.

[0004] Patent No. 6330641

[0005] Here, it is thought that one of the causes of the refrigerant settling in Patent Document 1 is that when the refrigerant is circulated through one of multiple evaporators while the inlet of the other evaporator is closed, the refrigerant flows into the other evaporator from the confluence.

[0006] Furthermore, since the refrigeration cycle is configured so that refrigerant oil circulates along with the refrigerant, if the refrigerant stagnates in one of the evaporators, some of the refrigerant oil will also stagnate in one of the evaporators. In other words, some of the refrigerant oil contained in the refrigerant circulating through the cycle will remain in the evaporator, causing a shortage of refrigerant oil and potentially affecting the operation of the compressor.

[0007] In view of the above, an object of the present disclosure is to provide a coupling member that includes a refrigerant confluence portion from each evaporator in a refrigeration cycle in which multiple evaporators are connected in parallel, and that can suppress stagnation of refrigerant and refrigeration oil in a specific evaporator.

[0008] A coupling member according to one aspect of the present disclosure is used in a refrigeration cycle having a first evaporator and a second evaporator connected in parallel to each other and configured to block the flow of a refrigerant containing refrigerant oil into the second evaporator. The coupling member has a first refrigerant flow path, a second refrigerant flow path, a junction, and a compressor-side flow path.

[0009] The first refrigerant flow path is for refrigerant flowing out from the first evaporator. The second refrigerant flow path is for refrigerant flowing out from the second evaporator. The confluence unit combines the refrigerant that has flowed through the first refrigerant flow path with the refrigerant that has flowed through the second refrigerant flow path. The compressor-side flow path guides the refrigerant that has flowed through the confluence unit to the intake port side of the compressor in the refrigeration cycle.

[0010] The second refrigerant flow path has an upstream portion, a downstream portion, and a connecting portion, and the downstream portion is located below the upstream portion in the direction of gravity. The upstream portion is located within the second refrigerant flow path on the refrigerant outlet side of the second evaporator. The downstream portion is located within the second refrigerant flow path on the confluence side. The connecting portion connects the upstream portion and the downstream portion in the second refrigerant flow path.

[0011] With this type of coupling member, the downstream portion of the second refrigerant flow path is positioned lower in the direction of gravity than the upstream portion, so that when the refrigerant flows from the junction to the second evaporator in the second refrigerant flow path, a portion (i.e., a connection portion) where the refrigerant flows against gravity can be created, thereby allowing the flow rate of the refrigerant from the junction to the second evaporator in the second refrigerant flow path to be reduced by the action of gravity.

[0012] Furthermore, since the downstream portion of the second refrigerant flow path is positioned lower in the direction of gravity than the upstream portion, the flow of refrigerant heading from the confluence portion toward the second evaporator can be forced against the inner wall surface of the connection portion, thereby suppressing the flow rate of the refrigerant.

[0013] That is, by configuring the coupling member so that the downstream portion of the second refrigerant passage is lower in the direction of gravity than the upstream portion, the flow rate of the refrigerant flowing from the junction to the second evaporator can be suppressed. As a result, when the coupling member is configured to allow the refrigerant to flow through the first evaporator and block the inflow of refrigerant to the second evaporator, the inflow of refrigerant and refrigeration oil from the junction to the second evaporator can be suppressed, thereby suppressing stagnation of the refrigerant and refrigeration oil in the second evaporator.

[0014] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0023] Fig. 1 is a perspective view showing the configuration of a coupling member according to a first embodiment; Fig. 2 is a configuration diagram of a vehicle air conditioning device according to a first embodiment; Fig. 3 is a configuration diagram of an interior air conditioning unit according to a first embodiment; Fig. 4 is an explanatory diagram showing the arrangement of a coupling member in a refrigeration cycle; Fig. 5 is a front view of a coupling member according to a first embodiment; Fig. 6 is a plan view of a coupling member according to a first embodiment; Fig. 7 is a right side view of a coupling member according to a first embodiment; Fig. 8 is a left side view of a coupling member according to a first embodiment; Fig. 9 is a perspective view showing the configuration of a coupling member according to a second embodiment;

[0015] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment may be assigned the same reference numerals, and duplicate descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other previously described embodiments may be applied to the other parts of the configuration. In addition to combinations of parts that are specifically specified as being combinable in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

[0016] First Embodiment A first embodiment of the present disclosure will be described with reference to the drawings. A coupling member 100 according to the first embodiment constitutes a part of a refrigerant circuit of a refrigeration cycle 10 in a vehicle air conditioner 1 shown in Fig. 2. The refrigeration cycle 10 is constituted by connecting multiple evaporators (i.e., an interior evaporator 15, a chiller 16) in parallel, and the coupling member 100 constitutes a refrigerant flow path including a refrigerant merging portion 13b that merges the flows of refrigerant flowing out from the multiple evaporators.

[0017] In the first embodiment, the vehicle air conditioner 1 to which the coupling member 100 is applied is used as a vehicle air conditioner for an electric vehicle that obtains driving power for running the vehicle from an electric motor. The vehicle air conditioner 1 conditions the air in the vehicle cabin, which is the space to be air-conditioned, and adjusts the temperature of a battery 31, which is a heat-generating device, in the electric vehicle.

[0018] The vehicle air conditioner 1 can switch between a cooling mode, a heating mode, and a dehumidifying and heating mode as air conditioning operation modes for air conditioning the vehicle cabin. The cooling mode is an operation mode in which the air blown into the vehicle cabin is cooled and then blown into the vehicle cabin. The heating mode is an operation mode in which the air blown into the vehicle cabin is heated and then blown into the vehicle cabin. The dehumidifying and heating mode is an operation mode in which the cooled and dehumidified air is reheated and then blown into the vehicle cabin, thereby dehumidifying and heating the vehicle cabin.

[0019] Furthermore, the automotive air conditioner 1 can switch between cooling and non-cooling the battery 31 regardless of the state of the air conditioning operation mode. Therefore, the operation mode of the automotive air conditioner 1 can be defined by a combination of the state of the air conditioning operation mode and the state of cooling and non-cooling the battery 31. Therefore, the operation modes of the automotive air conditioner 1 include seven operation modes: cooling mode, heating mode, dehumidifying heating mode, single cooling mode, cooling and cooling mode, cooling and heating mode, and cooling and dehumidifying heating mode.

[0020] The single cooling mode is an operation mode in which the battery 31 is cooled without air-conditioning the vehicle interior. The cooling and air-conditioning mode is an operation mode in which the vehicle interior is cooled and the battery 31 is cooled. The cooling and heating mode is an operation mode in which the vehicle interior is heated and the battery 31 is cooled. The cooling and dehumidifying heating mode is an operation mode in which the vehicle interior is dehumidified and heated and the battery 31 is cooled.

[0021] The refrigeration cycle 10 of the vehicle air conditioner 1 uses an HFC refrigerant (specifically, R134a) as the refrigerant, forming a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant. Refrigerant oil is mixed with the refrigerant to lubricate the compressor 11. The refrigerant oil used is polyalkylene glycol (PAG) oil, which is compatible with liquid-phase refrigerants. A portion of the refrigerant oil circulates through the cycle together with the refrigerant.

[0022] Next, a specific configuration of the vehicle air conditioner 1 according to the first embodiment will be described with reference to Fig. 2. The vehicle air conditioner 1 according to the first embodiment includes a refrigeration cycle 10, a heating section 20, a low-temperature side heat medium circuit 30, an interior air conditioning unit 40, and a control device 50.

[0023] First, a description will be given of the components constituting the refrigeration cycle 10 in the vehicle air conditioner 1. The refrigeration cycle 10 is a vapor compression type refrigeration cycle device.

[0024] First, the compressor 11 in the refrigeration cycle 10 draws in, compresses, and discharges refrigerant. The compressor 11 is located under the hood of the vehicle. The compressor 11 is an electric compressor that rotates a fixed-displacement compression mechanism with a fixed discharge capacity using an electric motor. The rotation speed (i.e., refrigerant discharge capacity) of the compressor 11 is controlled by a control signal output from the control device 50.

[0025] The discharge port of the compressor 11 is connected to an inlet side of a refrigerant passage 12a of the heat medium refrigerant heat exchanger 12. The heat medium refrigerant heat exchanger 12 is a radiator that radiates heat from the high-pressure refrigerant discharged from the compressor 11 to a high-temperature side heat medium circulating in a high-temperature side heat medium circuit 21 of the heating unit 20, thereby heating the high-temperature side heat medium.

[0026] The heat medium-refrigerant heat exchanger 12 has a refrigerant passage 12a through which the refrigerant of the refrigeration cycle 10 flows, and a heat medium passage 12b through which the high-temperature side heat medium of the high-temperature side heat medium circuit 21 flows. The heat medium-refrigerant heat exchanger 12 is formed of the same type of metal (aluminum alloy in the first embodiment) that has excellent heat conductivity, and each component is integrated by brazing.

[0027] As a result, the high-pressure refrigerant flowing through the refrigerant passage 12a and the high-temperature heat medium flowing through the heat medium passage 12b can exchange heat with each other. The heat medium-refrigerant heat exchanger 12 is an example of a condenser that dissipates heat from the high-pressure refrigerant, and constitutes a part of the heating unit 20 described below. The high-temperature heat medium flowing through the heat medium passage 12b can be a solution containing ethylene glycol, an antifreeze solution, or the like.

[0028] A refrigerant branching section 13a having a three-way joint structure is connected to the outlet of the refrigerant passage 12a of the heat medium-refrigerant heat exchanger 12. The refrigerant branching section 13a branches the flow of the liquid-phase refrigerant flowing out of the heat medium-refrigerant heat exchanger 12. The refrigerant branching section 13a has three inlet / outlets, one of which is a refrigerant inlet and the other two are refrigerant outlets.

[0029] One refrigerant outlet of the refrigerant branching section 13a is connected to the refrigerant inlet side of the indoor evaporator 15 via a first expansion valve 14a. The other refrigerant outlet of the refrigerant branching section 13a is connected to the refrigerant inlet side of the chiller 16 via a second expansion valve 14b.

[0030] The first expansion valve 14a is a pressure reducing unit that reduces the pressure of the refrigerant flowing out from one of the refrigerant outlets of the refrigerant branch unit 13a at least in the cooling mode. The first expansion valve 14a is an electrically operated variable throttle mechanism that includes a valve body and an electric actuator. That is, the first expansion valve 14a is a so-called electric expansion valve.

[0031] The valve element of the first expansion valve 14a is configured to change the passage opening (i.e., the throttle opening) of the refrigerant passage. The electric actuator has a stepping motor that changes the throttle opening of the valve element. The operation of the first expansion valve 14a is controlled by a control signal output from the control device 50.

[0032] The first expansion valve 14a is a variable throttle mechanism that has a full opening function that fully opens the refrigerant passage when the throttle opening is fully opened, and a full closing function that closes the refrigerant passage when the throttle opening is fully closed. In other words, the first expansion valve 14a can prevent the refrigerant from decompressing by fully opening the refrigerant passage.

[0033] The first expansion valve 14a closes the refrigerant passage, thereby blocking the inflow of refrigerant into the indoor evaporator 15. That is, the first expansion valve 14a functions both as a pressure reducing unit that reduces the pressure of the refrigerant and as a refrigerant circuit switching unit that switches the refrigerant circuit.

[0034] The outlet of the first expansion valve 14a is connected to the refrigerant inlet side of the indoor evaporator 15. The indoor evaporator 15 is an evaporator that, at least in the cooling mode, exchanges heat between the low-pressure refrigerant decompressed by the first expansion valve 14a and the blown air W to evaporate the low-pressure refrigerant and cool the blown air W.

[0035] 3, the interior evaporator 15 is disposed in a casing 41 of the interior air conditioning unit 40. That is, the interior evaporator 15 corresponds to an example of an air conditioning evaporator, and the first expansion valve 14a corresponds to an example of a cooling pressure reducing section.

[0036] 2, a second expansion valve 14b is connected to the other refrigerant outlet of the refrigerant branch portion 13a. The second expansion valve 14b is a pressure reducing portion that reduces the pressure of the refrigerant flowing out from the other refrigerant outlet of the refrigerant branch portion 13a at least in the cooling mode.

[0037] The second expansion valve 14b is an electrically operated variable throttle mechanism, similar to the first expansion valve 14a, and includes a valve body and an electric actuator. That is, the second expansion valve 14b is an electrically operated expansion valve, and has a fully open function and a fully closed function.

[0038] In other words, the second expansion valve 14b can prevent the refrigerant from decompressing by fully opening the refrigerant passage, and can also block the inflow of refrigerant to the chiller 16 by closing the refrigerant passage. That is, the second expansion valve 14b functions both as a pressure reducing unit that reduces the pressure of the refrigerant and as a refrigerant circuit switching unit that switches the refrigerant circuit.

[0039] The outlet of the second expansion valve 14b is connected to the refrigerant inlet side of the chiller 16. The chiller 16 is a heat exchanger that exchanges heat between the low-pressure refrigerant decompressed by the second expansion valve 14b and the low-temperature side heat medium circulating through the low-temperature side heat medium circuit 30.

[0040] The chiller 16 has a refrigerant passage 16a through which the low-pressure refrigerant decompressed by the second expansion valve 14b flows, and a heat medium passage 16b through which the low-temperature heat medium circulating in the low-temperature heat medium circuit 30 flows. Therefore, the chiller 16 is an evaporator that evaporates the low-pressure refrigerant and absorbs heat from the low-temperature heat medium by heat exchange between the low-pressure refrigerant flowing through the refrigerant passage 16a and the low-temperature heat medium flowing through the heat medium passage 16b. In other words, the chiller 16 corresponds to an example of an evaporator, and the second expansion valve 14b corresponds to an example of a pressure reducing section.

[0041] 2, the inlet side of an evaporation pressure regulating valve 17 is connected to the refrigerant outlet of the indoor evaporator 15. The evaporation pressure regulating valve 17 is an evaporation pressure adjusting unit that maintains the refrigerant evaporation pressure in the indoor evaporator 15 at or above a predetermined reference pressure. The evaporation pressure regulating valve 17 is configured as a mechanical variable throttle mechanism that increases the valve opening degree as the refrigerant pressure on the outlet side of the indoor evaporator 15 increases.

[0042] The evaporation pressure regulating valve 17 is configured to maintain the refrigerant evaporation temperature in the interior evaporator 15 at a reference temperature (1° C. in this embodiment) or higher that can prevent frost from forming on the interior evaporator 15 .

[0043] One refrigerant inlet of the refrigerant junction 13b is connected to the outlet of the evaporation pressure adjustment valve 17. The other refrigerant inlet of the refrigerant junction 13b is connected to the refrigerant outlet of the chiller 16. The refrigerant junction 13b has a three-way joint structure similar to that of the refrigerant branching section 13a, with two of the three inlet and outlet ports serving as refrigerant inlets and the remaining one serving as a refrigerant outlet.

[0044] The refrigerant junction 13b joins the flow of refrigerant flowing out from the indoor evaporator 15 and the flow of refrigerant flowing out from the chiller 16 via the evaporation pressure regulating valve 17. The refrigerant outlet of the refrigerant junction 13b is connected to the suction port side of the compressor 11.

[0045] 2, the interior evaporator 15 and the chiller 16 are connected in parallel to each other in the refrigeration cycle 10 of the vehicle air conditioner 1. Therefore, in the first embodiment, the interior evaporator 15 corresponds to an example of a first evaporator, and the chiller 16 corresponds to an example of a second evaporator.

[0046] The coupling member 100 according to the first embodiment constitutes a part of the refrigerant flow path including the refrigerant junction 13b in the refrigeration cycle 10. As shown in Fig. 2, the coupling member 100 has a flow path extending from the refrigerant outlet side of the indoor evaporator 15 to the refrigerant junction 13b, a flow path extending from the refrigerant outlet side of the chiller 16 to the refrigerant junction 13b, and a flow path extending from the refrigerant junction 13b to the suction port side of the compressor 11. The specific configuration of the coupling member 100 will be described later.

[0047] Next, a description will be given of the heating unit 20 in the vehicle air conditioner 1. The heating unit 20 is configured to heat the blown air W to be supplied to the space to be air-conditioned, using the high-pressure refrigerant in the refrigeration cycle 10 as a heat source.

[0048] The heating unit 20 according to the first embodiment is configured by a high-temperature side heat medium circuit 21. The high-temperature side heat medium circuit 21 is a heat medium circuit that circulates a high-temperature side heat medium, and as the high-temperature side heat medium, a solution containing ethylene glycol, an antifreeze solution, or the like can be used.

[0049] The high-temperature side heat medium circuit 21 of the heating section 20 is arranged with the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12, a radiator 22, a heater core 23, an electric heater 24, a high-temperature side flow control valve 25, a high-temperature side pump 26, etc.

[0050] As described above, in the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12, the high-temperature side heat medium is heated by heat exchange with the high-pressure refrigerant flowing through the refrigerant passage 12a. That is, the high-temperature side heat medium is heated using the heat pumped up by the refrigeration cycle 10.

[0051] The radiator 22 is a heat exchanger that exchanges heat between the high-temperature side heat medium heated by the heat medium-refrigerant heat exchanger 12 or the like and the outside air OA blown by an outside air fan (not shown), thereby radiating the heat of the high-temperature side heat medium to the outside air OA. The radiator 22 corresponds to an example of an outside air radiator.

[0052] The radiator 22 is disposed at the front side inside the vehicle hood. As the above-described outside air fan is operated, outside air OA flows from the front side of the vehicle to the rear and passes through the heat exchange portion of the radiator 22. When the vehicle is traveling, airflow from the front side of the vehicle to the rear side can be directed onto the radiator 22.

[0053] The heater core 23 is a heat exchanger that exchanges heat between the high-temperature heat medium heated in the heat medium-refrigerant heat exchanger 12 or the like and the blown air W that has passed through the indoor evaporator 15, thereby heating the blown air W. Therefore, the heater core 23 corresponds to an example of a heating heat exchanger. As shown in FIG. 3 , the heater core 23 is disposed in a casing 41 of the indoor air conditioning unit 40.

[0054] An electric heater 24 is connected to one inlet / outlet of the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12. The electric heater 24 is a heating device that generates heat when supplied with electric power and heats the high-temperature side heat medium flowing through the heat medium passage of the electric heater 24.

[0055] For example, a PTC heater having a PTC element (i.e., a positive temperature coefficient thermistor) can be used as the electric heater 24. The electric heater 24 can arbitrarily adjust the amount of heat for heating the high-temperature side heat medium by a control voltage output from the control device 50.

[0056] One of the inlet and outlet ports of the high-temperature side flow control valve 25 is connected to the outlet side of the heat medium passage of the electric heater 24. The high-temperature side flow control valve 25 is configured as an electric three-way flow control valve having three inlet and outlet ports. The other of the inlet and outlet ports of the high-temperature side flow control valve 25 is connected to the inlet port of the heater core 23. The remaining inlet and outlet port of the high-temperature side flow control valve 25 is connected to the inlet port of the radiator 22.

[0057] Therefore, in the high-temperature side heat medium circuit 21, the radiator 22 and the heater core 23 are connected in parallel with respect to the flow of the high-temperature side heat medium passing through the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12. The high-temperature side flow control valve 25 can continuously adjust the flow rate ratio between the flow rate of the high-temperature side heat medium flowing into the heater core 23 and the flow rate of the high-temperature side heat medium flowing into the radiator 22 in the high-temperature side heat medium circuit 21.

[0058] A confluence portion of a three-way joint structure is connected to the outlet of the radiator 22 and the outlet of the heater core 23. The confluence portion uses one of the three inlet / outlet ports of the three-way joint structure as an outlet and the remaining two as inlet / outlets. Therefore, the confluence portion can merge the flow of high-temperature side heat medium that has passed through the radiator 22 and the flow of high-temperature side heat medium that has passed through the heater core 23.

[0059] The outlet at the junction is connected to the suction port of the high-temperature side pump 26. The high-temperature side pump 26 is a heat medium pump that pumps the high-temperature side heat medium in order to circulate it in the high-temperature side heat medium circuit 21. The high-temperature side pump 26 is an electric pump whose rotation speed (i.e., pumping capacity) is controlled by a control voltage output from the control device 50. The discharge port of the high-temperature side pump 26 is connected to the inlet / outlet on the other side of the heat medium passage 12b of the heat medium-refrigerant heat exchanger 12.

[0060] As shown in FIG. 2 , the high-temperature side heat medium circuit 21 can continuously adjust the flow rate of the high-temperature side heat medium flowing toward the radiator 22 side and the flow rate of the high-temperature side heat medium flowing toward the heater core 23 side by using the high-temperature side flow control valve 25 arranged at the branching section.

[0061] In other words, by controlling the operation of the high-temperature side flow control valve 25, it is possible to adjust the amount of heat of the high-temperature side heat medium radiated to the outside air OA by the radiator 22 and the amount of heat of the high-temperature side heat medium radiated to the blown air W by the heater core 23.

[0062] Next, a description will be given of the low-temperature side heat medium circuit 30 in the vehicle air conditioner 1. The low-temperature side heat medium circuit 30 is a heat medium circuit that circulates a low-temperature side heat medium. As the low-temperature side heat medium, a fluid similar to the high-temperature side heat medium in the high-temperature side heat medium circuit 21 can be used.

[0063] The low-temperature side heat medium circuit 30 is arranged with the heat medium passage 16b of the chiller 16, a battery 31, an outside air heat exchanger 32, a low-temperature side flow rate adjustment valve 33, and a low-temperature side pump 34. The outlet of the heat medium passage 16b of the chiller 16 is connected to the suction port side of the low-temperature side pump 34.

[0064] The low-temperature side pump 34 is a heat medium pump in the low-temperature side heat medium circuit 30 that pumps out the low-temperature side heat medium that has passed through the heat medium passage 16b of the chiller 16. The basic configuration of the low-temperature side pump 34 is similar to that of the high-temperature side pump 26.

[0065] A branching section having a three-way joint structure is connected to the discharge port side of the low-temperature side pump 34. The branching section uses one of the three inlet / outlet ports of the three-way joint structure as an inlet and the remaining two as outlet ports. Therefore, the branching section can branch the flow of the low-temperature side heat medium pumped from the low-temperature side pump 34 into two flows.

[0066] One outlet of the branched portion of the low-temperature side heat medium circuit 30 is connected to an inlet side of a heat medium passage of a battery 31. The battery 31 supplies power to various electrical devices of the vehicle and is, for example, a rechargeable secondary battery (in this embodiment, a lithium ion battery). The battery 31 generates heat during charging and discharging, and is therefore an example of a heat-generating device.

[0067] The battery 31 is a so-called assembled battery formed by stacking multiple battery cells and electrically connecting these battery cells in series or parallel. This type of battery 31 is prone to a decrease in output at low temperatures and to accelerated deterioration at high temperatures. For this reason, the temperature of the battery 31 must be maintained within an appropriate temperature range (e.g., 15°C or higher and 55°C or lower) that allows the charge / discharge capacity of the battery 31 to be fully utilized.

[0068] In the vehicle air conditioner 1, the low-temperature side heat medium is passed through the heat medium passage of the battery 31 to exchange heat, thereby absorbing heat generated in the battery 31 into the low-temperature side heat medium, thereby adjusting the temperature of the battery 31. That is, the battery 31 is connected to the low-temperature side heat medium circuit 30 so that it can be cooled by the low-temperature side heat medium, and the temperature of the battery 31 can be maintained within a predetermined temperature range.

[0069] The other outlet of the branched portion of the low-temperature side heat medium circuit 30 is connected to the inlet side of an outdoor air heat exchanger 32. The outdoor air heat exchanger 32 is a heat exchanger that exchanges heat between the low-temperature side heat medium discharged from the low-temperature side pump 34 and outdoor air OA blown by an outdoor air fan (not shown).

[0070] The outside-air heat exchanger 32 is disposed at the front side of the drive unit compartment. Therefore, when the vehicle is traveling, traveling wind can be applied to the outside-air heat exchanger 32. Therefore, the outside-air heat exchanger 32 may be formed integrally with the radiator 22 or the like.

[0071] 2, a low-temperature side flow rate adjustment valve 33 is connected to the outlet side of the heat medium passage of the battery 31 and the outlet side of the outside-air heat exchanger 32. The low-temperature side flow rate adjustment valve 33 is configured as an electric three-way flow rate adjustment valve having three inlet and outlet ports.

[0072] That is, one of the inlet / outlet ports of the low-temperature side flow rate adjustment valve 33 is connected to the outlet side of the heat medium passage of the battery 31, and another of the inlet / outlet ports of the low-temperature side flow rate adjustment valve 33 is connected to the outlet side of the outside-air heat exchanger 32. Another of the inlet / outlet ports of the low-temperature side flow rate adjustment valve 33 is connected to the inlet side of the heat medium passage 16b of the chiller 16.

[0073] Therefore, the low-temperature side heat medium circuit 30 can switch the flow of the low-temperature side heat medium in the low-temperature side heat medium circuit 30 by controlling the operation of the low-temperature side flow rate adjustment valve 33. For example, with regard to the flow of the low-temperature side heat medium passing through the heat medium passage 16b of the chiller 16, the low-temperature side flow rate adjustment valve 33 can continuously adjust the flow rate ratio between the flow rate of the low-temperature side heat medium passing through the outside-air heat exchanger 32 and the flow rate of the low-temperature side heat medium passing through the heat medium passage of the battery 31.

[0074] That is, the vehicle air conditioner 1 can cool and regulate the temperature of the battery 31 by using the low-temperature side heat medium circuit 30. Furthermore, the vehicle air conditioner 1 can use the outside air OA as a heat source by using the outside air heat exchanger 32.

[0075] Next, the interior air conditioning unit 40 constituting the vehicle air conditioner 1 will be described with reference to Fig. 3. The interior air conditioning unit 40 is a unit in the vehicle air conditioner 1 for blowing out the blown air W, whose temperature has been adjusted by the refrigeration cycle 10, to an appropriate location within the vehicle cabin. The interior air conditioning unit 40 is disposed inside the instrument panel at the front end of the vehicle cabin.

[0076] The interior air conditioning unit 40 is configured by accommodating a blower 42, the interior evaporator 15, the heater core 23, etc. in an air passage formed inside a casing 41 that forms the outer shell of the unit. The casing 41 forms an air passage for the ventilation air W that is blown into the vehicle cabin. The casing 41 is molded from a resin (specifically, polypropylene) that has a certain degree of elasticity and excellent strength.

[0077] 3, an inside / outside air switching device 43 is disposed on the most upstream side of the blown air flow of the casing 41. The inside / outside air switching device 43 switches between introducing inside air (air inside the vehicle cabin) and outside air (air outside the vehicle cabin) into the casing 41.

[0078] The inside / outside air switching device 43 continuously adjusts the opening areas of the inside air inlet, which introduces inside air, and the outside air inlet, which introduces outside air, into the casing 41, using an inside / outside air switching door, thereby changing the ratio of the amount of inside air introduced to the amount of outside air introduced. The inside / outside air switching door is driven by an electric actuator for the inside / outside air switching door. The operation of this electric actuator is controlled by a control signal output from the control device 50.

[0079] A blower 42 is disposed downstream of the inside / outside air switching device 43 in the flow of blown air. The blower 42 is an electric blower that drives a centrifugal multi-blade fan with an electric motor. The blower 42 blows air drawn in through the inside / outside air switching device 43 toward the vehicle interior. The rotation speed (i.e., blowing capacity) of the blower 42 is controlled by a control voltage output from the control device 50.

[0080] The interior evaporator 15 and the heater core 23 are arranged in this order with respect to the flow of the air blown by the blower 42. That is, the interior evaporator 15 is arranged upstream of the heater core 23 with respect to the flow of the air blown.

[0081] A cool air bypass passage 45 is formed within the casing 41. The cool air bypass passage 45 is an air passage that allows the blown air W that has passed through the interior evaporator 15 to bypass the heater core 23 and flow downstream.

[0082] An air mix door 44 is disposed downstream of the interior evaporator 15 in the flow of blown air and upstream of the heater core 23. The air mix door 44 adjusts the ratio of the amount of blown air W passing through the heater core 23 and the amount of blown air W passing through the cool air bypass passage 45 after passing through the interior evaporator 15.

[0083] The air mix door 44 is driven by an electric actuator for driving the air mix door, and the operation of this electric actuator is controlled by a control signal output from a control device 50.

[0084] A mixing space 46 is provided downstream of the heater core 23 in the flow of blown air. In the mixing space 46, the blown air W heated by the heater core 23 and the blown air W that has passed through the cool air bypass passage 45 and has not been heated by the heater core 23 are mixed.

[0085] Furthermore, openings for blowing out the blown air (conditioned air) mixed in the mixing space 46 into the vehicle compartment are arranged at the most downstream portion of the casing 41 in the blown air flow direction. These openings include a face opening, a foot opening, and a defroster opening (none of which are shown).

[0086] The face opening is an opening for blowing conditioned air toward the upper bodies of occupants in the vehicle cabin, the foot opening is an opening for blowing conditioned air toward the feet of occupants, and the defroster opening is an opening for blowing conditioned air toward the inside surface of the window glass at the front of the vehicle.

[0087] These face opening holes, foot opening holes, and defroster opening holes are connected to face air outlets, foot air outlets, and defroster air outlets (none of which are shown) provided in the vehicle cabin via ducts that form air passages, respectively.

[0088] Therefore, the temperature of the conditioned air mixed in the mixing space 46 is adjusted by the air mix door 44 adjusting the ratio of the air volume passing through the heater core 23 to the air volume passing through the cold air bypass passage 45. This also adjusts the temperature of the blown air (conditioned air) blown into the vehicle compartment from each air outlet.

[0089] A face door, a foot door, and a defroster door (none of which are shown) are disposed upstream of the face opening, foot opening, and defroster opening in the flow of blown air, respectively. The face door adjusts the opening area of ​​the face opening. The foot door adjusts the opening area of ​​the foot opening. The defroster door adjusts the opening area of ​​the defroster opening.

[0090] The face door, foot door, and defroster door constitute an air outlet mode switching device that switches the air outlet from which conditioned air is blown out. The face door, foot door, and defroster door are connected to an electric actuator for driving the air outlet mode door via a link mechanism or the like, and are rotated in conjunction with each other. The operation of this electric actuator is controlled by a control signal output from the control device 50.

[0091] Next, a control system of the vehicle air conditioner 1 according to the first embodiment will be described with reference to Fig. 2. The control device 50 is composed of a well-known microcomputer including a CPU, ROM, RAM, etc., and its peripheral circuits.

[0092] The control device 50 performs various calculations and processes based on the control programs stored in its ROM, and controls the operation of various controlled devices connected to its output side. The controlled devices include the compressor 11, first expansion valve 14a, second expansion valve 14b, electric heater 24, high-temperature side quantity adjustment valve 25, high-temperature side pump 26, low-temperature side flow rate adjustment valve 33, and low-temperature side pump 34. The controlled devices also include the devices and actuators that make up the indoor air conditioning unit 40. Therefore, the controlled devices include the blower 42, inside / outside air switching device 43, and actuators for the air mix door.

[0093] A group of sensors for controlling air conditioning is connected to the input side of the control device 50. The group of sensors for controlling air conditioning includes an inside air temperature sensor, an outside air temperature sensor, a solar radiation sensor, a high pressure sensor, a first evaporator temperature sensor, a second evaporator temperature sensor, a blown air temperature sensor, and a battery temperature sensor. Detection signals from this group of sensors for controlling air conditioning are input to the control device 50.

[0094] The inside air temperature sensor is an inside air temperature detector that detects the temperature inside the vehicle cabin (inside air temperature) Tr. The outside air temperature sensor is an outside air temperature detector that detects the temperature outside the vehicle cabin (outside air temperature) Tam. The solar radiation sensor is an solar radiation amount detector that detects the amount of solar radiation As irradiating the vehicle cabin. The high-pressure sensor is a refrigerant pressure detector that detects the high-pressure refrigerant pressure Pd in ​​the refrigerant flow path from the discharge port side of the compressor 11 to the inlet side of the first expansion valve 14a or the second expansion valve 14b.

[0095] The first evaporator temperature sensor is an evaporator temperature detector that detects the refrigerant evaporation temperature (evaporator temperature) Tefin in the interior evaporator 15. The second evaporator temperature sensor is a temperature detector that detects the refrigerant evaporation temperature in the chiller 16, which corresponds to the second evaporator. As shown in Figures 1 and 2, the second evaporator temperature sensor 51 is disposed on the outlet side of the refrigerant passage 16a of the chiller 16, and detects the temperature of the refrigerant flowing out of the refrigerant passage 16a of the chiller 16.

[0096] The blown air temperature sensor is a blown air temperature detector that detects the blown air temperature TAV blown into the vehicle cabin. The battery temperature sensor is a battery temperature detector that detects the battery temperature TBA, which is the temperature of the battery 31. The battery temperature sensor has multiple temperature detectors that detect the temperatures of multiple locations on the battery 31. This allows the control device 50 to detect temperature differences between various locations on the battery 31. Furthermore, the average value of the detected values ​​from the multiple temperature detectors is used as the battery temperature TBA.

[0097] A plurality of heat medium temperature sensors are connected to the input side of the control device 50 in order to detect the temperature of the heat medium in each of the high-temperature side heat medium circuit 21 and the low-temperature side heat medium circuit 30. The vehicle air conditioner 1 switches the flow of the heat medium in the high-temperature side heat medium circuit 21 and the low-temperature side heat medium circuit 30 of the heating unit 20 by referring to the detection results of the plurality of heat medium temperature sensors. In this way, the vehicle air conditioner 1 can manage heat in the vehicle using the high-temperature side heat medium and the low-temperature side heat medium.

[0098] Furthermore, an operation panel located near the instrument panel at the front of the vehicle interior is connected to the input side of the control device 50. A plurality of operation switches are arranged on the operation panel. Therefore, operation signals from the plurality of operation switches are input to the control device 50. The various operation switches on the operation panel include an auto switch, an air conditioning switch, an air volume setting switch, a temperature setting switch, etc.

[0099] The auto switch is operated to set or cancel automatic control operation of the automotive air conditioner 1. The cooling switch is operated to request cooling of the vehicle cabin. The air volume setting switch is operated to manually set the air volume of the blower 42. And the temperature setting switch is operated to set a target temperature Tset for the vehicle cabin.

[0100] In addition, the control device 50 has an integrated control unit that controls various controlled devices connected to its output side, and the configuration (hardware and software) that controls the operation of each controlled device constitutes the control unit that controls the operation of each controlled device.

[0101] Next, the operation of the automotive air conditioner 1 according to the first embodiment will be described. As described above, the automotive air conditioner 1 according to the first embodiment can switch between a plurality of operating modes as needed. The switching between these operating modes is performed by executing a control program stored in advance in the control device 50.

[0102] More specifically, the control program calculates a target outlet temperature TAO of the air to be blown into the vehicle cabin based on detection signals detected by a group of air conditioning control sensors and operation signals output from the operation panel.

[0103] Specifically, the target air outlet temperature TAO is calculated by the following formula F1: TAO=Kset×Tset−Kr×Tr−Kam×Tam−Ks×As+C (F1), where Tset is the target temperature inside the vehicle cabin set by the temperature setting switch (vehicle cabin set temperature), Tr is the inside air temperature detected by the inside air temperature sensor, Tam is the outside air temperature detected by the outside air temperature sensor, and As is the amount of solar radiation detected by the solar radiation sensor. Kset, Kr, Kam, and Ks are control gains, and C is a correction constant.

[0104] In the control program, when the air conditioner switch on the operation panel is turned on and the target air outlet temperature TAO is lower than a predetermined cooling reference temperature α, the air conditioning operation mode is switched to the cooling mode.

[0105] The control program also switches the air conditioning operation mode to the dehumidifying / heating mode when the air conditioner switch on the operation panel is turned on and the target air outlet temperature TAO is equal to or higher than the cooling reference temperature α, and switches the air conditioning operation mode to the heating mode when the air conditioner switch is not turned on and the target air outlet temperature TAO is equal to or higher than the cooling reference temperature α.

[0106] The control program then switches between cooling and non-cooling of the battery 31 depending on the battery temperature TBA. Specifically, when the battery temperature TBA becomes equal to or higher than the reference battery temperature KTBA, the control program switches to an operation mode in which the battery 31 is cooled.

[0107] Therefore, the operation mode of the automotive air conditioner 1 is determined by a combination of the air conditioning operation mode and an operation mode indicating whether or not to cool the battery 31. For example, when the battery temperature TBA is equal to or higher than the reference battery temperature KTBA while the air conditioning of the vehicle compartment is not being performed, the operation mode of the automotive air conditioner 1 is switched to the single cooling mode in which the battery 31 is cooled without performing air conditioning of the vehicle compartment.

[0108] Therefore, the operating modes of the vehicle air conditioner 1 include a cooling mode, a heating mode, a dehumidifying heating mode, a single cooling mode, a cooling and cooling mode, a cooling and heating mode, and a cooling and dehumidifying heating mode. Of these, the cooling mode and the single cooling mode are described as operating modes that use any one of the multiple evaporators (indoor evaporator 15, chiller 16) connected in parallel, and the cooling and cooling mode is described as an operating mode that uses all of the multiple evaporators.

[0109] (A) Cooling Mode The cooling mode is an operating mode in which the blown air W is cooled by the interior evaporator 15 and blown into the vehicle cabin without cooling the battery 31. In this cooling mode, the control device 50 opens the first expansion valve 14a by a predetermined throttle opening and fully closes the second expansion valve 14b.

[0110] Therefore, in the refrigeration cycle 10 in the cooling mode, a refrigerant circulation circuit is formed in which the refrigerant flows in the order of the compressor 11, the heat medium refrigerant heat exchanger 12, the first expansion valve 14a, the indoor evaporator 15, the evaporation pressure control valve 17, and the compressor 11. That is, in the cooling mode, the refrigerant circuit is switched to one in which the blown air W blown by the blower 42 is cooled by the indoor evaporator 15.

[0111] In this cycle configuration, the control device 50 controls the operation of various control target devices connected to the output side so that they operate in a manner determined for the cooling mode. For example, the control device 50 controls the operation of the compressor 11 so that the refrigerant evaporation temperature Tefin detected by the first evaporator temperature sensor becomes the target evaporation temperature TEO.

[0112] Therefore, the vehicle air conditioner 1 in the cooling mode can cool the vehicle interior by blowing the blown air W cooled by the interior evaporator 15 into the vehicle interior. Here, in the refrigeration cycle 10 in the cooling mode, the second expansion valve 14b is controlled to a fully closed state. Therefore, the refrigerant inlet side of the refrigerant passage 12a of the chiller 16 is closed, so that the flow of refrigerant into the chiller 16 can be said to be in a state of being blocked.

[0113] (B) Single Cooling Mode The single cooling mode is an operating mode in which the air conditioning in the vehicle cabin is not performed, but the battery 31 is cooled. In this single cooling mode, the control device 50 opens the second expansion valve 14b to a predetermined throttle opening and fully closes the first expansion valve 14a.

[0114] Therefore, the refrigeration cycle 10 in the single cooling mode forms a heat pump cycle in which the refrigerant circulates in the order of the compressor 11, the heat medium-refrigerant heat exchanger 12, the second expansion valve 14b, the chiller 16, and the compressor 11. In addition, the low-temperature side heat medium circuit 30 in the single cooling mode is configured so that the low-temperature side heat medium circulates via the battery 31 and the chiller 16. That is, in the single cooling mode, the refrigerant is caused to flow into the chiller 16, and the refrigerant circuit is switched to one that can pump heat absorbed from the low-temperature side heat medium in the low-temperature side heat medium circuit 30 to the high-temperature side heat medium in the heating unit 20.

[0115] In this cycle configuration, the control device 50 controls the operation of various controlled devices connected to the output side so that they operate in a manner determined for the single cooling mode. For example, the control device 50 controls the operation of the compressor 11 so that the refrigerant discharge capacity determined for the single cooling mode is achieved.

[0116] Therefore, in the vehicle air conditioning device 1 in the single cooling mode, the low-temperature side heat medium can be cooled by absorbing heat from the low-temperature side heat medium in the chiller 16, and the battery 31 can be cooled by the cooled low-temperature side heat medium.

[0117] In the refrigeration cycle 10 in the single cooling mode, the first expansion valve 14a is controlled to a fully closed state, and therefore, the refrigerant inlet of the indoor evaporator 15 is closed, so that the inflow of refrigerant to the indoor evaporator 15 is blocked.

[0118] (C) Cooling / Cooling Mode The cooling / cooling mode is an operation mode in which the interior evaporator 15 cools the blown air W and blows it into the vehicle cabin, in parallel with cooling the battery 31. In this cooling / cooling mode, the control device 50 opens the first expansion valve 14a and the second expansion valve 14b to predetermined throttle openings.

[0119] Therefore, in the refrigeration cycle 10 in the cooling / air-cooling mode, the refrigerant circulates in the order of the compressor 11, the heat medium refrigerant heat exchanger 12, the first expansion valve 14a, the indoor evaporator 15, the evaporation pressure control valve 17, and the compressor 11. At the same time, the refrigerant circulates in the order of the compressor 11, the heat medium refrigerant heat exchanger 12, the second expansion valve 14b, the chiller 16, and the compressor 11. In the low-temperature side heat medium circuit 30 in the cooling / air-cooling mode, the low-temperature side heat medium circulates via the battery 31 and the chiller 16, as in the single cooling mode.

[0120] That is, in the refrigeration cycle 10 in the cooling / air-conditioning mode, a heat pump cycle is configured in which the indoor evaporator 15 and the chiller 16 are connected in parallel to the flow of refrigerant flowing out from the heat medium refrigerant heat exchanger 12 .

[0121] In this cycle configuration, the control device 50 controls the operation of various controlled devices connected to the output side so that they operate in a manner determined for the cooling / air-conditioning mode. For example, the control device 50 controls the operation of the compressor 11 so that the refrigerant discharge capacity determined for the cooling / air-conditioning mode is achieved.

[0122] Therefore, in the vehicle air conditioner 1 in the cooling / air-conditioning mode, the chiller 16 can cool the low-temperature side heat medium by absorbing heat from the low-temperature side heat medium, and the cooled low-temperature side heat medium can cool the battery 31. At the same time, the vehicle air conditioner 1 can cool the vehicle interior by blowing the blown air W cooled by the interior evaporator 15 into the vehicle interior.

[0123] In the refrigeration cycle 10 in the cooling / air-conditioning mode, the first expansion valve 14 a and the second expansion valve 14 b are controlled to predetermined throttle states, so that the refrigerant is allowed to flow into the refrigerant inlet of the indoor evaporator 15 and the refrigerant inlet of the heat medium passage 16 b of the chiller 16.

[0124] In a configuration in which multiple evaporators (e.g., the indoor evaporator 15 and the chiller 16) are connected in parallel, such as the refrigeration cycle 10 according to the first embodiment, it is possible that refrigerant stagnation may occur in a specific evaporator depending on the manner of switching between operation modes. As described above, since the refrigerant also contains refrigerant oil, if refrigerant stagnation occurs in an evaporator, the refrigerant oil will also stagnate in the evaporator.

[0125] Specifically, when the operating mode of the refrigeration cycle 10 in which air flows through two evaporators connected in parallel (for example, the cooling / air-conditioning mode described above) is switched to the operating mode of the refrigeration cycle 10 in which air flows through only one of the two evaporators connected in parallel, stagnation such as air conditioning occurs.

[0126] As in the refrigeration cycle 10 shown in FIG. 2, the refrigerant and refrigerating machine oil will be considered in the above case by taking as an example a refrigeration cycle having an indoor evaporator 15 and a chiller 16 connected in parallel.

[0127] First, the refrigeration cycle is operating in an operation mode (i.e., cooling / air-conditioning mode) in which refrigerant flows through both the indoor evaporator 15 and the chiller 16. From this state, the system switches to an operation mode (i.e., cooling mode) in which refrigerant continues to flow into the indoor evaporator 15 while blocking refrigerant from flowing into the chiller 16.

[0128] At this time, the control device 50 switches the second expansion valve 14b from the throttled state in the cooling / air-conditioning mode to the fully closed state. Because the first expansion valve 14a maintains the throttled state, the refrigerant in the cooling mode circulates through the compressor 11, the heat medium refrigerant heat exchanger 12, the first expansion valve 14a, the indoor evaporator 15, the evaporation pressure control valve 17, and the compressor 11 in this order.

[0129] On the other hand, since the second expansion valve 14b is fully closed, no refrigerant flows from the chiller 16 toward the refrigerant junction 13b in the refrigerant flow path downstream of the second expansion valve 14b and upstream of the refrigerant junction 13b.

[0130] Focusing on refrigerant junction 13b, the refrigerant continues to flow from the outlet side of indoor evaporator 15 toward the suction side of compressor 11, but no refrigerant flows in the flow path toward the outlet side of refrigerant passage 16a of chiller 16. Therefore, it is expected that part of the refrigerant flows toward the outlet side of refrigerant passage 16a of chiller 16 in the process of flowing from the outlet side of indoor evaporator 15 toward the suction side of compressor 11.

[0131] As described above, since the second expansion valve 14b blocks the flow of refrigerant into the chiller 16, it is expected that the refrigerant flowing from the refrigerant junction 13b will flow into the chiller 16 through its outlet and become stagnant inside the chiller 16.

[0132] If the refrigerant and refrigeration oil become stagnant inside the chiller 16, the refrigerant and refrigeration oil will continue to remain inside the chiller 16, resulting in a shortage of the amounts of refrigerant and refrigeration oil circulating through the cycle. If the refrigerant and refrigeration oil circulating through the cycle are insufficient, it is expected that this will result in a shortage of cooling capacity in the refrigeration cycle 10 and affect the operation of the compressor 11 that constitutes the refrigeration cycle 10.

[0133] The coupling member 100 according to the first embodiment is a coupling member that constitutes a refrigerant flow path including a refrigerant junction 13b in a refrigeration cycle 10 in which multiple evaporators are connected in parallel. The coupling member 100 suppresses refrigerant stagnation that occurs when switching from an operation mode in which two evaporators (an indoor evaporator 15 and a chiller 16) are used simultaneously to an operation mode in which the indoor evaporator 15 is used and the flow of refrigerant into the chiller 16 is blocked.

[0134] As shown in FIGS. 1 and 4 , the coupling member 100 according to the first embodiment is configured such that a first refrigerant flow path 101, a second refrigerant flow path 102, and a compressor-side flow path 103 are arranged around the refrigerant junction 13 b.

[0135] The first refrigerant flow path 101 is a refrigerant flow path that extends from the outlet side of the interior evaporator 15, which corresponds to the first evaporator, toward the refrigerant junction 13b. As shown in Fig. 1, in the coupling member 100 according to the first embodiment, the first refrigerant flow path 101 extends substantially horizontally from the right toward the refrigerant junction 13b.

[0136] Here, it is sufficient that the first refrigerant flow path 101 is connected at least to the outlet side of the indoor evaporator 15, and components of the refrigeration cycle 10 may be included between the end of the first refrigerant flow path 101 and the outlet side of the indoor evaporator 15. In the coupling member 100 of the first embodiment, the first refrigerant flow path 101 is connected to the outlet side of the evaporation pressure control valve 17.

[0137] The second refrigerant flow path 102 is a refrigerant flow path that extends from the outlet side of the refrigerant passage 16a of the chiller 16, which corresponds to the second evaporator, toward the refrigerant junction 13b, and is composed of an upstream section 102a, a connection section 102b, and a downstream section 102c. The second refrigerant flow path 102 extends from the rear side toward the refrigerant junction 13b located in front.

[0138] The upstream portion 102a constitutes a refrigerant flow path on the refrigerant outlet side of the chiller 16, which corresponds to the second evaporator, within the second refrigerant flow path 102. The downstream portion 102c constitutes a refrigerant flow path on the refrigerant junction 13b side within the second refrigerant flow path 102. The connection portion 102b constitutes a refrigerant flow path that connects the upstream portion 102a and the downstream portion 102c within the second refrigerant flow path 102.

[0139] 1 and 5 to 8, the downstream portion 102c is disposed below the upstream portion 102a in the direction of gravity in the second refrigerant flow path 102. As described above, the connecting portion 102b connects the upstream portion 102a and the downstream portion 102c, and therefore the connecting portion 102b is disposed to extend in a vertical direction in the direction of gravity.

[0140] 1 and 7 , the first refrigerant flow path 101 is disposed so as to be located at a position equal to or higher than the downstream portion 102c of the second refrigerant flow path 102 in the direction of gravity. That is, in the coupling member 100 according to the first embodiment, the downstream portion 102c of the second refrigerant flow path 102 is the refrigerant flow path located lowest in the direction of gravity.

[0141] The compressor-side flow path 103 is a refrigerant flow path that connects the refrigerant junction 13b and the suction port side of the compressor 11. As shown in Fig. 1 , in the coupling member 100 according to the first embodiment, the compressor-side flow path 103 extends leftward from the refrigerant junction 13b and is positioned so as to be positioned higher as it moves leftward.

[0142] The sensor mounting portion 104 is formed in the second refrigerant flow path 102 of the joint member 100, and is a mounting portion to which a second evaporator temperature sensor 51 is attached, which detects the state of the refrigerant flowing out from the chiller 16, which corresponds to the second evaporator. As shown in Figures 6 to 8, the sensor mounting portion 104 is located at a position on the connection portion 102b side in the upstream portion 102a of the second refrigerant flow path 102.

[0143] 1 and 4 to 8, the compressor-side flow path 103 is disposed above the refrigerant junction 13b and the first refrigerant flow path 101 in the direction of gravity. In this state, the first refrigerant flow path 101 is disposed at a position equal to or higher than the downstream portion 102c of the second refrigerant flow path 102 in the direction of gravity.

[0144] In the coupling member 100 according to the first embodiment configured as described above, the downstream portion 102c of the second refrigerant flow path 102 is positioned lower than the upstream portion 102a in the direction of gravity. As a result, when the refrigerant flows from the refrigerant junction 13b to the chiller 16 in the second refrigerant flow path 102, a portion (i.e., the connection portion 102b) where the refrigerant flows against gravity can be created.

[0145] As a result, with the coupling member 100, the flow rate of the refrigerant in the second refrigerant flow path 102 from the refrigerant junction 13b toward the chiller 16 can be suppressed by the action of gravity when the operation mode of the refrigeration cycle is switched. Furthermore, because the downstream portion 102c of the second refrigerant flow path 102 is disposed below the upstream portion 102a in the direction of gravity, the connection portion 102b is configured to extend upward and downward in the direction of gravity.

[0146] Therefore, when a refrigerant flow from the refrigerant junction 13b toward the chiller 16 occurs, the refrigerant flow can be directed against the inner wall surface of the connection part 102b, thereby suppressing the flow rate of the refrigerant. Furthermore, the flow of the refrigerant when flowing into the connection part 102b is restricted by the upper end side of the inner wall surface of the downstream part 102c.

[0147] That is, by configuring the coupling member 100 so that the downstream portion 102c of the second refrigerant flow path 102 is located lower in the direction of gravity than the upstream portion 102a, it is possible to suppress the flow rate of the refrigerant flowing from the refrigerant junction 13b to the chiller 16. As a result, when switching from the cooling / air-conditioning mode to the air-conditioning mode, the coupling member 100 suppresses the inflow of refrigerant and refrigeration oil from the refrigerant junction 13b to the chiller 16, thereby suppressing stagnation of the refrigerant and refrigeration oil in the chiller 16.

[0148] 6 , the downstream portion 102c of the second refrigerant flow path 102 is connected to the first refrigerant flow path 101 at the refrigerant junction 13b so as to form a predetermined angle θ with respect to the first refrigerant flow path 101. At the refrigerant junction 13b, the angle θ formed between the first refrigerant flow path 101 and the downstream portion 102c of the second refrigerant flow path 102 is determined so as to suppress the speed of the refrigerant flowing from the refrigerant junction 13b to the chiller 16 when switching from the cooling / air-conditioning mode to the cooling mode. Specifically, the angle θ is determined to be an acute angle or a right angle, and not an obtuse angle.

[0149] When the cooling mode is switched to the cooling mode, the refrigerant flows from the first refrigerant flow path 101 to the compressor side flow path 103 at the refrigerant junction 13b. Here, it is assumed that a portion of the refrigerant flowing through the first refrigerant flow path 101 flows into the second refrigerant flow path 102 at the refrigerant junction 13b.

[0150] In such a case, by setting the angle between the first refrigerant flow path 101 and the downstream portion 102c of the second refrigerant flow path 102 to a predetermined angle θ, the refrigerant can be caused to collide with the inner wall surfaces of the refrigerant flow paths at the refrigerant junction 13b, thereby slowing down the flow rate of the refrigerant. As a result, the coupling member 100 can suppress the inflow of refrigerant and refrigeration oil from the refrigerant junction 13b to the chiller 16, thereby suppressing stagnation of the refrigerant and refrigeration oil in the chiller 16.

[0151] As shown in FIGS. 1, 7, and 8, the upstream portion 102a of the second refrigerant flow path 102 is disposed so that at least a portion thereof is located above the upstream end of the connecting portion 102b in the direction of gravity.

[0152] As a result, the upstream portion 102a of the second refrigerant flow path 102 is located higher in the direction of gravity than the connecting portion 102b, and gravity can be used to direct the refrigerant from the upstream portion 102a to the connecting portion 102b. As a result, the coupling member 100 can suppress the inflow of refrigerant and refrigerating machine oil from the refrigerant junction 13b to the chiller 16, and suppress the stagnation of the refrigerant and refrigerating machine oil in the chiller 16.

[0153] 1 and 4 to 8, the compressor-side flow path 103 is disposed above the refrigerant junction 13b and the first refrigerant flow path 101 in the direction of gravity. In this state, the first refrigerant flow path 101 is disposed at a position equal to or higher than the downstream portion 102c of the second refrigerant flow path 102 in the direction of gravity.

[0154] This creates an up-and-down relationship in the direction of gravity between the first refrigerant flow path 101 and the downstream portion 102c of the second refrigerant flow path 102, thereby suppressing the flow of refrigerant and refrigeration oil from the refrigerant junction portion 13b into the chiller 16 and preventing the refrigerant and refrigeration oil from stagnating in the chiller 16.

[0155] 6 to 8, the sensor mounting portion 104 is disposed at a position on the connection portion 102b side in the upstream portion 102a of the second refrigerant flow path 102. The second evaporator temperature sensor 51 is attached to the sensor mounting portion 104.

[0156] By attaching the second evaporator temperature sensor 51 to the sensor mounting portion 104, the coupling member 100 and the second evaporator temperature sensor 51 can be unitized, and the detection accuracy of the state (e.g., temperature) of the refrigerant flowing out of the chiller 16 can be ensured.

[0157] As described above, according to the coupling member 100 according to the first embodiment, the downstream portion 102c of the second refrigerant flow path 102 is positioned lower than the upstream portion 102a in the direction of gravity. Therefore, when the refrigerant flows from the refrigerant junction 13b toward the chiller 16 in the second refrigerant flow path 102, a portion (i.e., the connection portion 102b) where the refrigerant flows against gravity can be created.

[0158] As a result, with coupling member 100, when the operation mode of the refrigeration cycle is switched, the flow rate of the refrigerant in second refrigerant flow path 102 from refrigerant junction 13b to chiller 16 can be suppressed by the action of gravity. Furthermore, when a flow of refrigerant occurs from refrigerant junction 13b to chiller 16, the refrigerant flow can be forced to collide against the inner wall surface of connection portion 102b, thereby suppressing the flow rate of the refrigerant.

[0159] That is, by configuring the coupling member 100 so that the downstream portion 102c of the second refrigerant flow path 102 is located lower in the direction of gravity than the upstream portion 102a, it is possible to suppress the flow rate of the refrigerant flowing from the refrigerant junction 13b to the chiller 16. As a result, when switching from the cooling / air-conditioning mode to the air-conditioning mode, the coupling member 100 suppresses the inflow of refrigerant and refrigeration oil from the refrigerant junction 13b to the chiller 16, thereby suppressing stagnation of the refrigerant and refrigeration oil in the chiller 16.

[0160] 6 , the downstream portion 102c of the second refrigerant flow path 102 is connected to the first refrigerant flow path 101 at the refrigerant junction 13b so as to form a predetermined angle θ with respect to the first refrigerant flow path 101. At the refrigerant junction 13b, the angle θ formed between the first refrigerant flow path 101 and the downstream portion 102c of the second refrigerant flow path 102 is determined so as to suppress the speed of the refrigerant flowing from the refrigerant junction 13b to the chiller 16 when switching from the cooling / air-conditioning mode to the cooling mode. Specifically, the angle θ is determined to be an acute angle or a right angle, and not an obtuse angle.

[0161] As a result, when switching from the cooling / air-conditioning mode to the air-conditioning mode, the coupling member 100 can collide the refrigerant against the inner wall surface of the refrigerant flow path at the refrigerant junction 13b, thereby slowing down the flow rate of the refrigerant and preventing the refrigerant and refrigeration oil from settling in the chiller 16.

[0162] As shown in FIGS. 1, 7, and 8, the upstream portion 102a of the second refrigerant flow path 102 is disposed so that at least a portion thereof is located above the upstream end of the connecting portion 102b in the direction of gravity.

[0163] This allows gravity to act so that the refrigerant flows from the upstream portion 102a of the second refrigerant flow path 102 to the connection portion 102b, thereby preventing the refrigerant and refrigerating machine oil from settling in the chiller 16.

[0164] The compressor-side flow path 103 is disposed above the refrigerant junction 13b and the first refrigerant flow path 101 in the direction of gravity. In this state, the first refrigerant flow path 101 is disposed at a position equal to or higher than the downstream portion 102c of the second refrigerant flow path 102 in the direction of gravity.

[0165] This creates an up-and-down relationship in the direction of gravity between the first refrigerant flow path 101 and the downstream portion 102c of the second refrigerant flow path 102, thereby suppressing the flow of refrigerant and refrigeration oil from the refrigerant junction portion 13b into the chiller 16 and preventing the refrigerant and refrigeration oil from stagnating in the chiller 16.

[0166] 6 to 8, the sensor mounting portion 104 is disposed at a position on the connection portion 102b side in the upstream portion 102a of the second refrigerant flow path 102. The second evaporator temperature sensor 51 is attached to the sensor mounting portion 104.

[0167] By attaching the second evaporator temperature sensor 51 to the sensor mounting portion 104, the coupling member 100 and the second evaporator temperature sensor 51 can be unitized, and the detection accuracy of the state (e.g., temperature) of the refrigerant flowing out of the chiller 16 can be ensured.

[0168] Second Embodiment Next, a second embodiment that differs from the above-described embodiment will be described with reference to Fig. 9 . In the second embodiment, the connection mode of the first refrigerant flow path 101 and the compressor-side flow path 103 at the refrigerant junction 13b of the coupling member 100 differs from that of the first embodiment. That is, other configurations of the coupling member 100 (the second refrigerant flow path 102, the sensor mounting portion 104) and the arrangement of the coupling member 100 in the refrigeration cycle 10 are the same as those of the first embodiment. Therefore, in the following description, differences from the first embodiment will be described in detail for the coupling member 100 according to the second embodiment, and descriptions of other parts will be omitted.

[0169] 9 , a coupling member 100 according to the second embodiment has a refrigerant junction 13b at its center, a first refrigerant flow path 101, a second refrigerant flow path 102, and a compressor-side flow path 103. The second refrigerant flow path 102 in the second embodiment has an upstream portion 102a, a connection portion 102b, and a downstream portion 102c, and is arranged in the same manner as in the first embodiment described above.

[0170] In the second embodiment, a sensor attachment portion 104 is also formed in the upstream portion 102a of the second refrigerant flow path 102, and the sensor attachment portion 104 is disposed on the connection portion 102b side of the upstream portion 102a.

[0171] The first refrigerant flow path 101 according to the second embodiment is a refrigerant passage that connects the outlet side of the interior evaporator 15, which corresponds to the first evaporator, to the refrigerant junction 13b. As shown in Fig. 9, the first refrigerant flow path 101 is connected to the refrigerant junction 13b so as to extend horizontally to the right and is disposed at approximately the same height as the downstream portion 102c of the second refrigerant flow path 102.

[0172] The compressor-side flow path 103 according to the second embodiment is a refrigerant passage that connects the refrigerant junction 13b to the suction port side of the compressor 11. The compressor-side flow path 103 according to the second embodiment is connected so as to extend leftward from the refrigerant junction 13b. Here, as shown in FIG. 1 and other figures, the compressor-side flow path 103 according to the first embodiment is configured so that the further leftward it is located, the higher it is in the direction of gravity. However, the compressor-side flow path 103 according to the second embodiment extends horizontally from the refrigerant junction 13b. That is, in the coupling member 100 according to the second embodiment, the first refrigerant flow path 101 and the compressor-side flow path 103 are disposed at equal positions in the direction of gravity.

[0173] As shown in FIG. 9 , in the refrigerant junction 13b of the coupling member 100 according to the second embodiment, the first refrigerant flow path 101 is arranged upstream of the downstream portion 102c of the second refrigerant flow path 102 with respect to the flow of refrigerant flowing to the compressor 11 via the refrigerant junction 13b.

[0174] As a result, with the coupling member 100 according to the second embodiment, when the mode is switched from the cooling / air-conditioning mode to the air-conditioning mode and refrigerant flows from the indoor evaporator 15 toward the compressor 11, the amount of refrigerant flowing into the second refrigerant flow path 102 can be suppressed at the refrigerant junction 13b. As a result, with the coupling member 100 according to the second embodiment, the inflow of refrigerant and refrigeration oil from the refrigerant junction 13b to the chiller 16 can be suppressed, and stagnation of the refrigerant and refrigeration oil in the chiller 16 can be suppressed.

[0175] As described above, according to the coupling member 100 of the second embodiment, even if the connection mode of the first refrigerant flow path 101 and the compressor side flow path 103 to the refrigerant merging portion 13b is different, it is possible to obtain the same functional effects as those of the above-mentioned embodiment due to the configuration and operation.

[0176] 9 , in the coupling member 100 according to the second embodiment, the first refrigerant flow path 101 and the compressor-side flow path 103 are arranged to be located on the same plane as the refrigerant junction 13b. In the coupling member 100 according to the second embodiment, the first refrigerant flow path 101 is arranged to be upstream of the downstream portion 102c of the second refrigerant flow path 102 with respect to the flow of refrigerant that flows to the compressor 11 via the refrigerant junction 13b.

[0177] As a result, with the coupling member 100 according to the second embodiment, when the mode is switched from the cooling / air-conditioning mode to the air-conditioning mode and refrigerant flows from the indoor evaporator 15 toward the compressor 11, the amount of refrigerant flowing into the second refrigerant flow path 102 can be suppressed at the refrigerant junction 13b. As a result, with the coupling member 100 according to the second embodiment, the inflow of refrigerant and refrigeration oil from the refrigerant junction 13b to the chiller 16 can be suppressed, and stagnation of the refrigerant and refrigeration oil in the chiller 16 can be suppressed.

[0178] The present disclosure is not limited to the above-described embodiments, and various modifications can be made as follows within the scope of the present disclosure.

[0179] In the above-described embodiment, the indoor evaporator 15 is used as the first evaporator, and the chiller 16 is used as the second evaporator, but the present invention is not limited to this. The first evaporator and the second evaporator may be evaporators that evaporate the refrigerant and exhibit a heat absorption effect. For example, both the first evaporator and the second evaporator may be air-conditioning evaporators, or may be chillers that absorb heat from a heat medium.

[0180] In the first embodiment described above, the compressor-side flow path 103 of the coupling member 100 is disposed so as to extend upward beyond the first refrigerant flow path 101 and the refrigerant junction 13b, but this is not limiting. For example, it is also possible to employ a configuration in which the compressor-side flow path 103 extends downward beyond the first refrigerant flow path 101 and the refrigerant junction 13b.

[0181] In the coupling member 100 according to the embodiment described above, the second evaporator temperature sensor 51 that detects the temperature of the refrigerant flowing out from the chiller 16 is attached to the sensor attachment portion 104, but the present disclosure is not limited to this. The sensor that can be attached to the sensor attachment portion according to the present disclosure may be any sensor that can detect the state of the refrigerant flowing out from the second evaporator, and may be, for example, a pressure sensor that detects the pressure of the refrigerant flowing out from the second evaporator.

[0182] The coupling member disclosed in this specification has the following features: (Item 1) A refrigeration cycle (10) has a first evaporator (15) and a second evaporator (16) connected in parallel with each other and configured to be able to block the flow of refrigerant containing refrigerating machine oil into the second evaporator, the coupling member (100) having: a first refrigerant flow path (101) through which refrigerant flowing out from the first evaporator flows, a second refrigerant flow path (102) through which refrigerant flowing out from the second evaporator flows, a junction section (13b) at which the refrigerant flowing through the first refrigerant flow path and the refrigerant flowing through the second refrigerant flow path are joined, and a compressor-side flow path (103) at which the refrigerant flowing through the junction section is led to a suction port side of a compressor in the refrigeration cycle, the second refrigerant flow path having: an upstream section (102a) of the second refrigerant flow path located on a refrigerant outlet side of the second evaporator; and a downstream section (102c) of the second refrigerant flow path located on the junction side. a connecting portion (102b) connecting the upstream portion and the downstream portion of the second refrigerant flow path, wherein the downstream portion is disposed below the upstream portion in the direction of gravity. (Item 2) The downstream portion (102c) of the second refrigerant flow path (102) is connected to the first refrigerant flow path (101) at the junction (13b) so as to form a predetermined angle (θ) with the first refrigerant flow path (101), and the angle (θ) formed by the downstream portion of the second refrigerant flow path and the first refrigerant flow path at the junction is determined so as to suppress a speed of the refrigerant flowing from the junction to the second refrigerant flow path when the refrigerant flows through the first evaporator (15) and flow into the second evaporator (16) is blocked. (Item 3) The coupling member according to Item 1 or 2, wherein the upstream portion (102 a) of the second refrigerant flow path (102) is positioned such that at least a portion thereof is located above an upstream end of the connecting portion (102 b) in the direction of gravity. (Item 4) The coupling member according to Item 3, wherein when the first refrigerant flow path (101) and the compressor-side flow path (103) are positioned at different positions in the direction of gravity, the first refrigerant flow path is positioned at least as high as the downstream portion (102 c) of the second refrigerant flow path (102) in the direction of gravity.(Item 5) The coupling member according to Item 3, wherein, when the first refrigerant flow path (101) and the compressor-side flow path (103) are arranged at equal positions in a gravity direction, the first refrigerant flow path is arranged upstream of the downstream portion (102c) of the second refrigerant flow path (102) in terms of the flow of the refrigerant flowing from the first evaporator to the compressor. (Item 6) The coupling member according to any one of Items 1 to 5, wherein a sensor mounting portion (104) is formed on the connection portion (102b) side of the upstream portion (102a) of the second refrigerant flow path (102) for mounting a refrigerant sensor (51) that detects a parameter indicative of a state of the refrigerant flowing out of the second evaporator.

[0183] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A refrigeration cycle (10) having a first evaporator (15) and a second evaporator (16) connected in parallel with each other and configured to be able to block the flow of refrigerant containing refrigerating machine oil into the second evaporator, a coupling member (100) having: a first refrigerant flow path (101) through which refrigerant flowing out from the first evaporator flows; a second refrigerant flow path (102) through which refrigerant flowing out from the second evaporator flows; a junction section (13b) that joins the refrigerant that has flowed through the first refrigerant flow path and the refrigerant that has flowed through the second refrigerant flow path; and a compressor-side flow path (103) that leads the refrigerant that has flowed through the junction section to a suction port side of a compressor in the refrigeration cycle, wherein the second refrigerant flow path has: an upstream section (102a) of the second refrigerant flow path that is located on the refrigerant outlet side of the second evaporator; and a downstream section (102c) of the second refrigerant flow path that is located on the junction side. a connecting portion (102b) that connects the upstream portion and the downstream portion in the second refrigerant flow path, wherein the downstream portion is disposed below the upstream portion in a gravitational direction.

2. A coupling member as described in claim 1, wherein the downstream portion (102c) of the second refrigerant flow path (102) is connected to the first refrigerant flow path (101) at the confluence (13b) so as to form a predetermined angle (θ), and the angle (θ) formed by the downstream portion of the second refrigerant flow path and the first refrigerant flow path at the confluence is determined so as to be able to suppress the speed of the refrigerant flowing from the confluence to the second refrigerant flow path when the refrigerant is circulating through the first evaporator (15) and its flow into the second evaporator (16) is blocked.

3. A coupling member as described in claim 1 or 2, wherein the upstream portion (102a) of the second refrigerant flow path (102) is arranged so that at least a portion thereof is positioned above the upstream end of the connection portion (102b) in the direction of gravity.

4. A coupling member as described in claim 3, wherein when the first refrigerant flow path (101) and the compressor side flow path (103) are arranged at different positions in the direction of gravity, the first refrigerant flow path is arranged so that it is higher than the downstream portion (102c) of the second refrigerant flow path (102) in terms of its positional relationship in the direction of gravity.

5. A coupling member as described in claim 3, wherein when the first refrigerant flow path (101) and the compressor side flow path (103) are arranged at positions equal to each other in the direction of gravity, the first refrigerant flow path is arranged upstream of the downstream portion (102c) of the second refrigerant flow path (102) in terms of the flow of the refrigerant flowing from the first evaporator to the compressor.

6. A coupling member as described in claim 1, wherein a sensor mounting portion (104) for mounting a refrigerant sensor (51) for detecting a parameter indicating the state of the refrigerant flowing out from the second evaporator is formed on the connection portion (102b) side in the upstream portion (102a) of the second refrigerant flow path (102).

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